"He ran into some people he knew and they were congratulating him on his engagement," the source tells Us.

Dave Franco, who's currently filming the "Neighbors" sequel that's due out next year, has reportedly been dating the "Mad Men" actress since January 2012, though the two have kept the relationship mostly under the radar.

They did play a couple in a seriously crude "Funny or Die" video that dropped in April 2013, and were caught funning around together in a photo that was one of the many revealing celebrity snaps stolen and leaked online in late 2014.

Instead, the pair was seen holding hands together as they went grocery shopping.

At the time, Brie was still on television shows like Community and Mad Men, while Franco had recently appeared in 21 Jump Street.

Even my parents, who are hippies, felt some kind of pressure, I’m sure. Want stories like these delivered straight to your inbox?

"I’ve never been the girl who’s planning my dream wedding — I was always practicing my speech for the Oscars.

That was my dream, which is kind of sad but kind of great," she said.

Should the film become a big hit with young audiences, like the studio anticipates and hopes, Dave Franco could establish himself as one of the next big movie stars, on par with what his brother, James, has been.

In addition to being a hugely successful actor, Franco is also in a long-term relationship with another successful actor, Alison Brie.